What does regex [*\f]+ mean?

Question

In the org-mode the outline-regexp variable is set to "[*\f]+".

I am not able to figure out what it stands for, referred this without success.

Edit:- [*\f]+ changed to "[*\f]+"

Solution 1

The default value matches asterisks and page breaks: "[*\f]+"

http://www.emacswiki.org/emacs/OutlineMode#toc2

Solution 2

\f stands for form feed, which is a special character used to instruct the printer to start a new page.

[*\f]+ Then means any sequence entirely composed of * and form feed, arbitrarily long.

Solution 3

C-hig (elisp) Regexp Special RET

Note also that the usual regexp special characters are not special
inside a character alternative.  A completely different set of
characters is special inside character alternatives: `]', `-' and `^'.

So [*\f]+ matches any sequence which is at least one character long, and contains (only) any number and combination of asterisks, backslashes, and the letter 'f'.

EDIT:

Ah, you actually meant "[*\f]", did you? That's not the same thing as the regexp [*\f] (as the latter would be represented in string read syntax as "[*\\f]").

Make sure you quote appropriately.

If you did mean "[*\f]" then the \f is indeed a form-feed, as indicated by the other answers.